Grinding wheel dressing apparatus

ABSTRACT

Grinding wheel dressing apparatus is disclosed in which the dressing tool is actuated by cam-operated compound motion slide means in order to describe an involute or similar curve e.g. for gear or splined shaft grinding purposes and in which a slide carrier for the compound slide means is arranged for angular setting in relation to the plane and corresponding flank profile of the grinding wheel and also in which the dressing tool is carried by the compound slide means for presentation to the flank profile with its axis substantially parallel to the average normal to the required flank profile curve while adjustable variable movement means is interposed between each slide of the compound motion slide means and cam mechanism thereto for obtaining variation in the extent of slide and tool movement according to the magnitude of the required curve.

United States Patent 72] Inventors Raymond Leslie Palmer Solihull;

Norman Darlington, Coventry, England [21] Appl. No. 729,268 [22] Filed May 15, 1968 [45] Patented Mar. 9, 1971 [73] Assignee Coventry Gauge & Tool Company Limited Coventry, England [54] GRINDING WHEEL DRESSING APPARATUS 3 Claims, 4 Drawing Figs. [52] U.S. Cl 125/11 [51] Int. Cl. B24!) 53/00 [50] Field olSearch 125/11 56] References Cited UNITED STATES PATENTS 2,317,411 4/1943 Seyferth 125/11 2,326,073 8/1943 Seyferth 125/11 3,339,537 9/1967 Stade 125/11 3,372,687 3/1968 Grabowski 125/11 Primary Examiner-Harold D. Whitehead Attorney- Watson, Cole, Grindle &.Watson ABSTRACT: Grinding wheel dressing apparatus is disclosed in which the dressing tool is actuated by cam-operated compound motion slide means in order to describe an involute or similar curve e.g. for gear or splined shaft grinding purposes and in which a slide carrier for the compound slide means is arranged for angular setting in relation to the plane and corresponding flank profile of the grinding wheel and also in which the dressing tool is carried by the compound slide means for presentation to the flank profile with its axis substantially parallel to the average normal to the required flank profile curve while adjustable variable movement means is interposed between each slide of the compound motion slide means and cam mechanism thereto for obtaining variation in the extent of slide and tool movement according to the magnitude of the required curve.

PATENTED HAR 91971 SHEET 2 [IF 2 INVENTORS.

RAYMOND LESLHZ P LME NORMAN DARLINQI'ON ATTORNEYS.

GRKNDTNG WHEEL DRESSING AlPlPARATlU The object of this invention is to provide an improved grinding wheel dressing apparatus for causing a dressing tool to describe a required curve eg of involute, cycloidal, Novikov or like form more particularly in the dressing or trueing of grinding wheels used for profile grinding of toothed or like components such as gears and splinecl shafts.

A particular object of the invention is to enable a wide variety of profile grinding wheel forms to be dressed in a universal manner especially as regards the required toothed form and/or gear diameter in the case of a gear grinding wheel without recourse to the use of former plates or templates, while a further object is to obtain optimum dressing tool presentation to a grinding wheel throughout the extent of the latters involute or other curved profile.

The foregoing and other practical advantages will be apparent from the following disclosure.

in the accompanying drawings:

FIG. 1 is an elevation of grinding wheel dressing apparatus embodying this invention and shown in position of use,

FIG. 2 is a sectional view taken on the line II II of FIG. 1,

FIG. 3 is a profile diagram and,

FIG. 4 is a diagrammatic indication of slide operating mechanism.

Referring to the drawings and in carrying the invention into practice it is hereafter described as applied to apparatus for dressing the profileor ribbed form of a gear grinding wheel 1 whereby both sides or flanks 2 of the wheel form can be dressed simultaneously by a pair of units 3,3 each carrying a dressing tool 4 for appropriate operation. Whereas it would be usual to use a pair of units 3,3 in this way, if desired one unit could be operated in relation to a single flank.

in use the pair of units 3,3 or their carrier frames 5,5 are pivotally or hingedly mounted about a common axis at 6 whereby the units 3,3 may be set to a required mutual inclination usually symmetrically in relation to a plane 7 (shown vertically disposed) containing the grinding wheel 1 and passing through the said pivotal axis 6 which axis is coaxial with that of a gear being ground, e.g. where the dressing apparatus is set up along with a gear being ground on a work head slide of a gear grinding machine for enabling the gear to be either positioned under the wheel for grinding or the apparatus to be brought under the wheel for dressing the latter. For mounting purposes the two dressing units 3,3 are pivotally carried in the above manner on a support base 8 by means ofa hinge pin 9.

Each dressing unit 3 is of similar construction but of opposite hand and each unit or frame thereof carries a compound slide assembly 10 in turn carrying or arranged to carry a dressing tool 4. For angular setting of the dressing units 3,3 in relation to the plane, 7, each dressing unit frame 5 is provided with an abutment face 11 preferably lying in a radial plane in relation to the axis 6 of the pivotal mounting of the units 3,3 and such that the abutment faces 11 of the two units are opposed to one another. Each unit 3 is set to the required angle in relation to the base by any convenient means such as one or more slip gauges interposed between the abutment face ill and a fixed central datum abutment 12 carried by an upstanding bracket 13 of the base 8 which abutment 12 is shown of cylindrical form having its axis lying in the said plane 7.

Normally both units 3,3 are set to the same angle relative to the plane 7 which angle may be of the order of 20 to 30 or thereabouts dependent on the nature of the required wheel profile and basis of operation of the dressing tools 4,4.

The slide assembly ill for the dressing tool 4 of each unit 3 consists of a main slide 14 slidable on the unit frame 5 in a direction parallel with the radial abutment face 11 of the latter while a subslide 15 carrying the dressing tool 4 operates at right angles to the main slide 14 and radial abutment face 11.

The slide assembly llll of each unit 3 is operated by a mechanism as described hereafter whereby required compound movement is imparted to the dressing tool 4 in accordance with the required involute or other curved form of corresponding flank f the grinding wheel profile.

The angle at which each dressing unit 3 is set is such that its radial abutment face 11 is at right angles or thereabouts to the average normal to the required curvature of the wheel profile 2 (having regard to the necessary extent of such curvature) so that the dressing tool 4 is presented to the profile 2 in a direction parallel with the said average normal while furthermore the coordinates of compound movement of the tool 4 as effected by the slide assembly 10 are established substantially about said average normal. The average normal N to a profile curve 2 and average slope S of the latter are indicated in FIG. 3. The inclination of each unit 3 is thus substantially parallel to the average slope.

Among other advantages this results in optimum presentation of the tool 4 to the profile 2 throughout the extent of the curvature of the latter so that contact of the dressing tool diamond with the wheel is localized for better accuracy of operation.

By simply altering the angle of inclination of each dressing unit 3 the tool 4 can be caused to follow an involute or other curve in a corresponding manner to that obtained by a previous setting so that dressing of the wheel 1 to suit different tooth gap widths can be readily obtained, i.e. as dictated by the number of teeth on the gear being ground.

As indicated at 18 provision should be made for adjusting the dressing tool mounting on the subslide 15 at right angles to the latter that is to say in a direction parallel with the inclination of the unit 3 or substantially at right angles to the axis of the tool 4 and the said average normal in order to obtain setting of the tool 4 in accordance with the diameter of the gear being ground.

' In view of the considerable variation afforded by the abovementioned unit angular settings and tool settings, corresponding compound movement of the tool 4 by the slide assembly 10 is required to suit each particular case and adjustable operating mechanism for this purpose may be as follows (reference being had to FIG. 4).

The main and subslides 14, 15 are arranged for cam operation in timed relationship with one another through the intermediary of adjustment means whereby the extent of slide movement in relation to rotation of its actuating cam can be varied according to the required compound movement of the tool 4.

Each slide 14, 15 is operated by a corresponding cam l6, 17 respectively and both cams provide a progressive rise which is preferably of constant rate in the case of the main slide cam 16 while the rise of the cam 17 to the subslide 15 is desirably of varying rate so as to cause the subslide 15 to move at a greater or less rate than the main slide 14 according to the required compound movement.

For obtaining adjustment of slide movement in relation to cam rotation and for example in the case of the main slide 14 the corresponding cam l6 cooperates with a follower 19 on an auxiliary slide slidable on the main frame 5 and carrying an angularly adjustable sine bar 21 which in turn cooperates with a follower 22 on the main slide 14 itself. Although movement of the auxiliary slide 20 always corresponds to the rotation of the cam to, corresponding movement of the main slide 14 is dependent on the angular setting of the sine bar 2 1.

In a similar manner the tool carrying subslide 15 is operated by its cam 17 through an auxiliary slide 23 carried by the main slide 14 and arranged to follow the corresponding cam 17 by a follower 24. The auxiliary slide 23 carries an angularly adjustable sine bar 25 cooperating with a follower 26 on the subslide 15 so that variation of the extent of movement of the subslide 15 in relation to rotation of its operating cam 17 can be varied by angular adjustment of the sine bar 25 on its as sociated auxiliary slide 23. The sine bars 21, 25 may be independently set to selected angular positions in any suitable manner such as by means of slip gauges.

The general form traced by each dressing tool 4 is dependent upon the form of the slide operating cams l6, 17 but the magnitude of the curve traced and the chordal width of the ribbed form on the grinding wheel are respectively determined by setting the sine bars 21, 25 and inclining the dressing units 3, 3 to appropriate angles.

The earns 16, 17 which may be coaxially mounted, are geardriven at 27 for back and forth rotation from a rack 29 operated for reciprocating movement such as by a hydraulic linear actuator 30.

In a convenient arrangement of providing common rack actuation of the gear drive 27 to the cams of each dressing unit 3 and further in accordance with this invention, a single rack 29 of cylindrical or part cylindrical form having annular teeth is provided about the pivotal axis 6 of the dressing units 3, 3 and is shown coaxially and slidably carried by the hinge pin 9 for the hinged mounting of the units 3, 3.

The rack 29 is reciprocated by the hydraulic actuator 30 shown provided in the mounting base 8 and the rack is engaged by the driving gear 27a of the cam drive 27 of each unit 3 so that the two driving gears 27a are mutually inclined in their engagement with the cylindrical rack 29.

In addition to providing a common drive to each dressing unit the arrangement of the cylindrical rack 29 at the pivotal axis 6 also permits angular setting of the units 3, 3 without interference with the cam drive 27 to the tool slide assemblies 10 of either unit.

If desired the timing and operation of suitable cams 16, 17 may be such that the tools 4, 4 are in contact with the grinding wheel 1 during an operative stroke but are moved clear during a return stroke, while the tool actuation may be such that dressing of the flat peripheral crest of the wheel 1 between the flanks 2, 2 is also effected.

For certain requirements of gear tooth or other form provision may be made for modifying the effective form of one or more of the cams more particularly the subslide cam 17 such as by means of a plate secured to the latter.

We claim:

1. Grinding wheel dressing apparatus for causing a dressing tool to describe a curve of the character described comprising support structure, a slide carrier pivotally mounted on said support structure for angular setting movement in relation to the plane and corresponding flank profile of a grinding wheel to be dressed; compound slide means carried by the slide carrier and of which one slide is slidable in a substantially radial direction relative to said pivotal mounting of the slide carrier while a further slide of said compound slide means is slidable at right angles to said direction; a dressing tool carried by said compound slide means for corresponding compound movement thereby and such that the axis of the dressing tool is at right angles to said direction and the tool is presented to a said corresponding flank profile of a grinding wheel with the tool axis substantially parallel to the average normal to the required curve of a said flank profile; cam mechanism carried by the carrier for imparting correlated movement to said slides of the compound motion slide means in order to cause the dressing tool to follow the required curve of a said flank profile; and adjustable variable movement means interposed between the cam mechanism and each said slide of the compound motion slide means for obtaining variation in the extent of movement of said slides by the cam mechanism according to the magnitude of the required flank profile curve.

2. Grinding wheel dressing apparatus according to claim 1 wherein the adjustable variable movement means interposed between the cam mechanism and each slide of the compound motion slide means consists of an auxiliary slide for actuation by the cam mechanism and angularly adjustable sine bar means carried by the auxiliary slide and coacting with a follower of said slide of the compound motion slide means for obtaining variation in the extent of movement of said lastmentioned slide on operation of the cam mechanism.

3. Grinding wheel dressing apparatus according to claim 1 wherein the slide carrier is arranged to be angularly set about the axis of a toothed rack of at least part cylindrical form and carried by the support structure, which rack is axially movable for actuating a gear drive to the cam mechanism. 

1. Grinding wheel dressing apparatus for causing a dressing tool to describe a curve of the character described comprising support structure, a slide carrier pivotally mounted on said support structure for angular setting movement in relation to the plane and corresponding flank profile of a grinding wheel to be dressed; compound slide means carried by the slide carrier and of which one slide is slidable in a substantially radial direction relative to said pivotal mounting of the slide carrier while a further slide of said compound slide means is slidable at right angles to said direction; a dressing tool carried by said compound slide means for corresponding compound movement thereby and such that the axis of the dressing tool is at right angles to said direction and the tool is presented to a said corresponding flank profile of a grinding wheel with the tool axis substantially parallel to the average normal to the required curve of a said flank profile; cam mechanism carried by the carrier for imparting correlated movement to said slides of the compound motion slide means in order to cause the dressing tool to follow the required curve of a said flank profile; and adjustable variable movement means interposed between the cam mechanism and each said slide of the compound motion slide means for obtaining variation in the extent of movement of said slides by the cam mechanism according to the magnitude of the required flank profile curve.
 2. Grinding wheel dressing apparatus according to claim 1 wherein the adjustable variable movement means interposed between the cam mechanism and each slide of the compound motion slide means consists of an auxiliary slide for actuation by the cam mechanism and angularly adjustable sine bar means carried by the auxiliary slide and coacting with a follower of said slide of the compound motion slide means for obtaining variation in the extent of movement of said lastmentioned slide on operation of the cam mechanism.
 3. Grinding wheel dressing apparatus according to claim 1 wherein the slide carrier is arranged to be angularly set about the axis of a toothed rack of at least part cylindrical form and carried by the support structure, which rack is axially movable for actuating a gear drive to the cam mechanism. 